This invention relates to identification systems in general and, more particularly, to an identification system using Computer Generated Moire (CGM).
Everyday and every single moment, important valid private identifications/documents (hereafter I/D's) are lost, stolen or counterfeited throughout the world. As I/D's are used for various purposes, once they fall into wrong hands, which on numerous occasions, results in signatures being imitated and used illegally, tremendous financial losses may be caused to the owners of the I/D's and the organizations that issued the I/D's.
The most frequent approach at present to stop or to reduce the illegal usage of a stolen/lost I/D is to provide a magnetic strip on it, and a computer read-out is used to verify this I/D card. Nevertheless, such verifications can only be done within the aid of computer terminals. Consequently, when those cards are used outside the network of 9 computer designated by the organization that issued the I/D's, such as abroad, computer verification is practically impossible.
Various systems hve been proposed to code the necessary specific information for I/D's. In the optical field, encoding and decoding techniques are disclosed in the following U.S. patents: 3,455,577 (U.V. or I.R. illumination of fluorescent material); 3,125,812 (fiber optic encoding and decoding of signature); 2,952,080 (crystographic grid scrambler information); 3,238,837 (multifiber image encoding and decoding); 3,256,767 (fiber optic scanning for encoding and decoding); 3,156,051 (random dot card and lens system); and 3,234,663 (film coding with different wavelength light sources). Several newer approaches based on the applications of holograms have been adopted lately, as disclosed in U.S. patents 3,647,275; 3,620,590; 3,668,795 (reference beam coded holograms); 3,483,513; 48,373; Swiss pat. 451,571; British pat. 1,188,302 (optical filtering based on Fourier holograms for pattern recognition) and U.S. Pat. No. 4,120,559 (sandwich holograms). Based on optical principles, these inventions are operative beyond the confinement of computer connections. But although a number of optical systems described in these patents provide secruity to some extent, they generally suffer from a variety of practical problems, for example, the expense, or complexity in commercial use. On the other hand, a number of other systems meet the cost requirements, but unfortunately do not provide the required level of security. More recently, some credit cards used embossed holograms, which have made counterfeiting more difficult, yet have not improved much on safeguarding against illegal usage of stolen/lost I/D's.